Lightness computation in simple and complex images

简单和复杂图像中的亮度计算

• 批准号: 0236701
• 负责人: Alan Gilchrist
• 金额: $ 22.25万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0236701&HistoricalAwards=false
• 关键词: Lightness; computation; simple; complex; images

How we distinguish black, white and gray surfaces has yet to be explained scientifically. With NSF support, Dr. Alan Gilchrist studies how the visual system determines the shades of gray in the world we see. Consider the follow: Under the same lighting, a white paper reflects more light to the eye than a black paper. But a black paper under brighter illumination can reflect much more light to the eye than a less- illuminated white paper. Nevertheless we see black as black and white as white. This is the kind of puzzle that Dr. Gilchrist attempts to understand. His studies progress from the simplest possible scenes. An observer's head is placed inside a large, opaque hemisphere that fills the observer's visual field. The inside surface divides vertically into two gray shades. Regardless of which shades are used, the lighter one always appears white. This is an important clue to the visual system. In these simple circumstances, it appears to assign white to the brightest part of the scene, but the relative area of the two regions, and the difference between their actual gray shades also play a role. Next to be studied are laboratory scenes that contain more than one region of illumination. Here the rules become more complex. The final studies in the series include complex, natural scenes using a new apparatus that can insert an artificial patch of gray onto any surface of the scene being viewed. This innovative use of technology sets the funded work apart from previous efforts. It allows investigators of lightness perception to conduct research on the richly complex surfaces that constitute real-world scenes. One broad impact of the work will be to make this technology and an illusion archive available to other scientists. In addition, understanding how gray shades are computed correctly in human vision will lead to programming advances in machine vision.

我们如何区分黑色、白色和灰色表面还没有得到科学的解释。在美国国家科学基金会的支持下，艾伦·吉尔克里斯特博士研究了视觉系统如何决定我们所看到的世界中的灰色阴影。考虑以下情况：在相同的照明下，白纸比黑纸向眼睛反射更多的光。但是，与照度较低的白纸相比，亮度较高的黑色纸张向眼睛反射的光线要多得多。尽管如此，我们还是把黑看成黑，把白看成白。这就是吉尔克里斯特博士试图理解的一种谜题。他的研究从最简单的场景开始。观察者的头部被放置在一个巨大的、不透明的半球内，这个半球充满了观察者的视野。内表面垂直分为两个灰色色调。无论使用哪种色调，浅色调总是显示为白色。这是视觉系统的一条重要线索。在这些简单的情况下，它似乎将白色指定给场景中最亮的部分，但两个区域的相对面积以及它们实际灰度级之间的差异也起到了作用。接下来要研究的是包含不止一个照明区域的实验室场景。在这里，规则变得更加复杂。该系列的最后研究包括复杂的自然场景，使用一种新的设备，可以将人工灰色斑块插入到正在观看的场景的任何表面。这种对技术的创新使用使资助的工作有别于以前的努力。它允许研究人员对构成真实世界场景的极其复杂的表面进行研究。这项工作的一个广泛影响将是使这项技术和幻觉档案可供其他科学家使用。此外，了解人类视觉中灰度级是如何正确计算的，将导致机器视觉的编程进步。